The invention provide a class of actinically-crosslinkable amphiphilic prepolymers which comprise at least one polysiloxane segment, at least one polyoxazoline segment, and two terminal ene groups. The present invention is also related to a medical device comprising a silicone hydrogel material obtained from step-growth polymerization of a polymerizable material comprising a prepolymer of the invention and to a method for producing contact lenses from a prepolymer of the invention.